Kinetic molecular theory of gases

Answer Key - Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   The gas in a sealed balloon goes from 300 K to 600 K. Average kinetic energy is proportional to kelvin temperature. By what factor does it change, Ari?

   2 times
2. 2.

   A sealed bottle of air goes from 250 K to 375 K. Average kinetic energy is proportional to kelvin temperature. By what factor does it change, Bo?

   1.5 times
3. 3.

   A sealed box of air goes from 280 K to 350 K. Average kinetic energy is proportional to kelvin temperature. By what factor does it change, to 0.01, Kira?

   1.25 times
4. 4.

   In kinetic molecular theory, how much of a gas's volume do the particles themselves take up, Luz?

   • Nearly the whole volume, once heated particles swell
   • Very little; a gas is mostly empty space
   • Most of it; the particles touch
5. 5.

   In kinetic molecular theory, what happens to the particles' total kinetic energy when they collide, Milo?

   • It stays the same: the collisions are elastic
   • It goes into making the particles bigger
   • It drops, so the particles slowly come to rest
6. 6.

   What causes the pressure inside a balloon, Noah?

   • The particles swelling against the rubber
   • The weight of gas particles resting on the bottom
   • Gas particles hitting the inside of the balloon
7. 7.

   A sealed syringe's plunger is pushed in at the same temperature. Why does the pressure rise, Ren?

   • The particles stop moving and pile up
   • The same particles hit the walls more often in less space
   • The particles get bigger when squeezed
8. 8.

   What does a gas's kelvin temperature measure, Tala?

   • The average kinetic energy of its particles
   • The size of its particles
   • How many particles it has
9. 9.

   At 0 K, what would gas particles' average kinetic energy be in kinetic theory, Zee?

   • Zero, but the particles would be at their largest size
   • Zero, since energy follows kelvins
   • The same as at room temperature
10. 10.

    Why must kinetic energy comparisons use kelvins, not °C, Esme?

    • Celsius numbers are too small to divide
    • Kelvins start at zero energy, so ratios make sense
    • Kelvins measure the particles' size